Indicator Post

ABSTRACT

This invention relates to an indicator post comprising an elongate sheet of high strength engineering polymer (HSEP) material, the elongate sheet being resiliently bendable to enable the indicator post to revert upright after an impact. An associated reinforcement means attachable to a driveable portion of the indicator post is also disclosed.

This application claims the benefit of Australian Application No.2008905490 filed Oct. 23, 2008, the content of which is hereinincorporated by reference.

TECHNICAL FIELD

The present invention relates to an indicator post. In a particularform, the present invention relates to a flexible indicator postsuitable for indicating the position of an object or delineating a road,lane way or the like.

BACKGROUND

Indicator posts are commonly employed by road traffic authorities tovisually indicate or delineate the location of roads, paths and lanes.Furthermore, indicator posts are often utilised by entities such aswater authorities, fire protection authorities and mining companies toindicate the position or location of important assets such as pipelines,valves and drains.

Flexible indicator posts are used in those situations where a post islikely to suffer from numerous impacts from either vehicles or otherobjects. The principle behind these flexible posts is that upon impactthey are able to flex and then subsequently return to a substantiallyupright position. In this manner, a flexible post is able to survive animpact unlike a standard rigid post which will either fracture or bendpermanently. As such, flexible posts will tend to have a greaterlifetime when compared to standard rigid posts resulting in reducedmaintenance costs.

One example of a flexible indicator post is a roadside post that isformed of a single elongate sheet of spring steel. However, there are anumber of serious disadvantages with these spring steel posts. Oneimportant disadvantage is that a spring steel post is likely to creasewhen subject to an impact such as a direct wheel over from a vehiclewhere the spring steel post is forced into a tight right angle bendthereby causing the spring steel to permanently deform. Anotherdisadvantage is that a spring steel post must be coated to both preventcorrosion and to ensure that it stands out visually. In addition, a postformed of a single sheet of spring steel can cause a substantial amountof damage to a vehicle striking it and in the case of a motorcyclist, aspring steel post may form a safety hazard especially if the post isstruck edge on. Furthermore, once a spring steel post has been damagedit cannot be easily recycled.

It is desirable to improve upon any one or more of the above identifiedshortcomings.

SUMMARY

In a first aspect the present invention accordingly provides anindicator post comprising an elongate sheet of high strength engineeringpolymer (HSEP) material, the elongate sheet resiliently bendable toenable the indicator post to revert upright after an impact.

In another form, the HSEP material is a UV stabilised extrudablepolycarbonate.

In another form, the UV stabilised extrudable polycarbonate is selectedfrom any one of Makrolon 3101, Panlite polycarbonate, Novarexpolycarbonate, Carbine 8073 polycarbonate or any combination thereof.

In another form, the elongate sheet has a substantially arcuatesectional profile.

In another form, the elongate sheet has a substantially channel shapedprofile.

In another form, the width is approximately between 40 mm and 140 mm.

In another form, the thickness is approximately between 1 mm and 6 mm.

In another form, the indicator post further includes ground engagingmeans to resist upward movement of the post after installation into theground.

In another form, the indicator post further includes an installationdepth indicator.

In another form, the indicator post further comprises a driveable baseportion attached to the elongate sheet.

In another form, the driveable base portion includes a star picketsection.

In another form, the indicator post includes reinforcement means toreinforce a drivable portion of the elongate sheet.

In another form, the reinforcement means substantially matches the shapeof the drivable portion of the elongate sheet.

In another form, the reinforcement means comprises an elongate webportion attached to the elongate sheet.

In another form, the elongate web portion includes a tapered end.

In another form, the elongate sheet is formed of steel.

In another form, the indicator post is a roadside post.

In a second aspect, the present invention accordingly provides areinforcement means for an indicator post, the reinforcement means beingattached to a driveable portion of the indicator post to reinforce thedriveable portion for driving into the ground.

In another form, the reinforcement means substantially matches the shapeof the drivable portion of the indicator post.

In another form, the reinforcement means comprises an elongate webportion.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative embodiments of the present invention will be discussed withreference to the accompanying drawings wherein:

FIG. 1 is a front view of an indicator post according to a firstillustrative embodiment of the present invention;

FIG. 2 is a bottom view of the indicator post as illustrated in FIG. 1;

FIG. 3 is a top view of the indicator post as illustrated in FIG. 1;

FIG. 4 is a side view of the indicator post as illustrated in FIG. 1;

FIG. 5 is a rear view of the indicator post as illustrated in FIG. 1;

FIG. 6 is a side view of the indicator post illustrated in FIG. 1 asinstalled in the ground;

FIG. 7 is a front view of an indicator post according to a secondillustrative embodiment of the present invention;

FIG. 8 is a bottom view of the indicator post as illustrated in FIG. 7;

FIG. 9 is a top view of the indicator post as illustrated in FIG. 7;

FIG. 10 is a side view of the indicator post as illustrated in FIG. 7;

FIG. 11 is a rear view of the indicator post as illustrated in FIG. 7;

FIG. 12 is a side view of the indicator post illustrated in FIG. 7 asinstalled in the ground;

FIG. 13 is a front view of an indicator post according to a thirdillustrative embodiment of the present invention;

FIG. 14 is a bottom view of the indicator post as illustrated in FIG.13;

FIG. 15 is a top view of the indicator post as illustrated in FIG. 13;

FIG. 16 is a side view of the indicator post as illustrated in FIG. 13;

FIG. 17 is a rear view of the indicator post as illustrated in FIG. 13;

FIG. 18 is a side view of the indicator post illustrated in FIG. 13 asinstalled in the ground; and

FIG. 19 is a series of sectional views of indicator posts in accordancewith further embodiments of the present invention.

In the following description, like reference characters designate likeor corresponding parts throughout the several views of the drawings.

TECHNICAL DESCRIPTION

Referring now to FIGS. 1 to 5, there is shown an indicator post 100 inaccordance with a first illustrative embodiment of the presentinvention. Indicator post 100 includes an elongate sheet 110 of highstrength engineering polymer (HSEP) such as a UV stabilised extrudablepolycarbonate having high flexural and impact strength and high heatresistance. In this illustrative embodiment, elongated sheet is formedof Makrolon™ 3103 available from Bayer Material Sciences. Other examplesof HSEP materials that are suitable include, but are not limited to,extrusion grade Panlite polycarbonate, Novarex polycarbonate or Carbine8073 polycarbonate. As would be apparent to those skilled in the art,HSEP materials provide the important advantage of being generallyrecyclable.

Elongate sheet 110 has a generally channel shaped cross sectionalprofile comprising a central web portion 111 and two opposed angledportions 112 (as best seen in FIGS. 2 and 3) with a pair oflongitudinally extending ribs 120 located at the boundary between thecentral web portion 111 and the angled portions 112.

Ribs 120 function to both stiffen elongate sheet 110 and to provide alongitudinally extending recessed portion 114, which at the top end ofelongate sheet 110 provides a protected area for retro-reflective sheetportion 150. In this manner, retro-reflective sheeting 150 is shieldedwhen indicator post 100 is struck by a vehicle and the top portionstrikes the ground. Indicator post 100 includes a tapered end 140 comingto a point 141 which aids in the driving of the post 100 into theground. While in this illustrative embodiment, the retro-reflectivesheet portion is employed to enhance the visual indicatingcharacteristics of indicator post 100, equally the top or other portionof post 100 may be coated with a suitable reflective coating orcombination of coatings. Furthermore, elongate sheet 110 may be extrudedin any desired colour unlike posts formed of spring steel which must beseparately coated to improve their visibility.

The lower portion of indicator post 100 further includes an upwardlyextending tongue 160 formed by punching a slot in elongate sheet 110which upon installation of the post 100 into the ground functions toresists upward movement of the post 100. Other ground engaging meansthat may be employed include a retention rod which extends horizontallythrough an aperture in the post and anchoring devices which may beattached or fastened to post 100 which extend either horizontally orupwardly and function to resist upward movement of post 100.

Post 100 further includes a depth marker line 130 extending horizontallyacross the front face of elongate sheet 110 which functions as aninstallation depth indicator. In another illustrative embodiment, asecond depth marker line is placed at the corresponding location on therear of post 100, thereby facilitating installation of post 100 to thecorrect depth from either direction. Other examples of installationdepth indicators include, but are not limited to, a depth marker holecomprising a single centrally located aperture located on the post atthe height corresponding to the depth that the indicator post 100 is tobe installed into the ground or a depth marker sticker or tag that issecured to the elongate sheet 110 by mechanical means and/or by anappropriate adhesive.

In this illustrative embodiment post 100 has a height of 1400 mm, awidth of 100 mm and a thickness of 4.0 mm. The angle that angledportions 112 subtend with respect to web portion 111 is approximately 45degrees. However, depending on the intended location and requirements,post 100 may range in height, thickness, width and channel angle asrequired. Some illustrative height ranges include, but are not limitedto, less than 400 mm, 400 mm to 600 mm, 600 mm to 800 mm, 800 mm to 1000mm, 1000 mm to 1200 mm, 1200 mm to 1400 mm, 1400 mm to 1600 mm, 1600 mmto 1800 mm, 1800 mm to 2000 mm and greater than 2000 mm.

Some illustrative thickness ranges include, but are not limited to, lessthan 1 mm, 1 mm to 1.5 mm, 1.5 mm to 2.0 mm, 2.5 mm to 3.0 mm, 3.5 mm to4.0 mm, 4.5 mm to 5.0 mm, 5.0 mm to 5.5 mm, 5.5 mm to 6.0 mm and greaterthan 6.0 mm. Some illustrative width ranges include, but are not limitedto, less than 40 mm, 40 mm to 60 mm, 60 mm to 80 mm, 80 mm to 100 mm,100 mm to 120 mm, 120 mm to 140 mm and greater than 140 mm. Someillustrative channel angles include, but are not limited to, 0 degrees(i.e. substantially flat) to 20 degrees, 20 degrees to 40 degrees, 40degrees to 60 degrees, 60 degrees to 80 degrees and greater than 80degrees.

In one illustrative embodiment, the manufacturing process for indicatorpost 100 involves feeding granules of HSEP material into a plasticextruder which melts and extrudes the molten HSEP material through a dieand then through an extrusion calibrator or sizing plate that forms andsets the post profile. The resultant extruded HSEP material is then fedthrough a cooling tank into a haul off or caterpillar drive which drawsand pulls the cooled HSEP material from the cooling tank to form acontinuous length of extruded HSEP material having the desired sectionalprofile. The cooled and extruded HSEP material then travels through acutting device which cuts the extruded HSEP material into posts of thedesired shape (e.g. a taper) and length.

Referring now to FIG. 6, there is shown indicator post 100 in operation.Indicator post 100 is installed in the ground 800 to the level of depthline marker 130. This installation may be accomplished in a number ofdifferent ways. In a first method of installing indicator post 100, ahole of larger size than the post may be dug or drilled to the suitabledepth, post 100 is then deposited in the hole and the hole thenrefilled. In a second method of installing indicator post 100, a smallpilot or lead hole is drilled into the ground 800 and post 100 may thenbe driven into the ground 800 either manually or by use of suitablepneumatic driving equipment. In a third method of instilling indicatorpost 100, the post may be driven into the ground 800 either manually orby pneumatic means without the use of a pilot hole.

In both the second and third methods of installation, the presence oftapered end 140 facilitates the installation of indicator post 100. In afourth method of installing indicator post 100, a section of the ground800 may be excavated and filled with a settable material such asconcrete. Before the settable material sets, indicator post is depositedinto the settable material in the upright position. As shown in FIG. 6,indicator post 100 when subject to an impact will resiliently bend andrecover to revert upright after the impact. In those circumstances whereindicator post 100 may subject to a tight right angle bend, such aswhere there is a direct wheel over by a vehicle, a recess may be formedin the ground immediately adjacent to the post to increase the bendradius at ground level.

Referring now to FIGS. 7 to 11, there is shown an indicator post 200 inaccordance with a second illustrative embodiment of the presentinvention. As with the first embodiment, indicator post 200 includes anelongate sheet 110 of HSEP material which in this illustrativeembodiment is formed from Makrolon™ 3103. Indicator post 200 alsoincludes a driveable base portion 210 including a base attachment plate240 welded to a star picket section 230 having a tapered end 240 andcoming to a point 241. Star picket section 230 functions as a rigidinsertion portion which is driven into the ground. In other embodiments,driveable base portion 210 may include a sharpened stake or a piece of asuitable rigid material having a channel or box section that may or maynot include a tapered end. Base attachment plate 240 is attached to thebottom end of elongate sheet 110 by a series of rivets 220 but equally,driveable base portion 210 may be attached to elongate sheet 110 byother suitable attachments means such as by the use of an adhesive orother mechanical attachment means. Although in this illustrativeembodiment, driveable base portion 210 has been utilised in combinationwith a HSEP material, equally driveable base portion 210 may be usedwith indicator posts formed of other materials.

Referring now to FIG. 12, there is shown indicator post 200 inoperation. In this illustrative embodiment, indicator post 200 isinstalled in the ground to the level of the top edge 241 of attachmentplate 240 which forms an installation depth indicator. As with indicatorpost 100 of the first illustrative embodiment, indicator post 200 may beinstalled in a number of different ways. However, the presence ofdriveable base portion 210 ensures that post 200 is more suitable to bedirectly driven into the ground 800. In one illustrative mode ofinstallation, a jackhammer is employed to drive driveable base portion210 by locating the end of a complementary tool inserted into thejackhammer into the notch 231 located at the top of star picket section230. In this method of installation, the jackhammer is alignedsubstantially parallel and against the indicator post 200 as aninstaller drives star picket section 230 into the ground 800. Dependingon the type of jackhammer, the indicator post 200 may be insertedthrough the handle of the jackhammer which will function to align andretain post 200 to the jackhammer to facilitate the installationprocess.

Referring now to FIGS. 13 to 17, there is shown an indicator post 300 inaccordance with a third illustrative embodiment of the presentinvention. Indicator post 300 is directed to those situations where itis desirable to directly drive post 300 into a relatively hard surfacesuch as a top layer of asphalt on a road or other compacted material anda substantially unitary post is required. In these situations, variousmaterials such as PVC plastic and to a lesser extent HSEP material maynot be suitably rigid to allow direct driveability into a hard surface.Indicator post 300 includes an elongate sheet 110 of HSEP material asdescribed with reference to the first illustrative embodiment of thepresent invention and further includes reinforcement means 400 attachedto a driveable portion 160 of elongate sheet 110 to reinforce thisportion for driving into a surface.

In this illustrative embodiment, reinforcement means 400 includes anelongate web 410 formed of suitable rigid material such as galvanisedsteel having a thickness of 1 to 3 mm that is sized and shaped to sit inrecessed portion 114 located between ribs 120 at the lower end ofelongate sheet 110. Although in this illustrative embodiment,reinforcement means 400 is formed from galvanised steel, equally otherrigid materials such as various type of steels, wood or rigid plasticmaterials may be employed.

Reinforcement means 400 is attached in this illustrative embodiment tothe driveable portion of elongate sheet 110 by a series of spaced apartrivets 420 extending along the length of web 410. Equally however,reinforcement means 400 may be attached to the elongate sheet by otherattachment means such as the use of bolts or attachment tags which arefolded around and crimped onto elongate sheet 110. In anotherillustrative embodiment, reinforcement means may be formed ascomplementary shaped sleeve or cap which receives and is attached to thedriveable portion of elongate sheet 110.

Web 410 includes at the driveable end a taper 440 coming to a point 441which substantially matches in shape the corresponding tapered portion140 of elongate sheet 110, thereby reinforcing this region so that it isdirectly driveable into relatively hard surfaces. As would beappreciated by those skilled in the art, reinforcement means 400 may beapplicable to all types of indicator posts formed from differentmaterials which may require reinforcement to ensure driveability intorelatively hard surfaces. While in this illustrative embodiment,reinforcement means 400 is shaped to substantially conform or match withthe driveable portion 160 of elongate sheet 110, equally other shapedreinforcement means that function to reinforce the driveable portion 160of elongate sheet 110 are contemplated to within the scope of theinvention. In another illustrative embodiment, reinforcement meansconsists of reinforced edging that extends around the perimeter of thedriveable portion of elongate sheet 110.

Referring now to FIG. 18, there is shown indicator post 300 inoperation. Indicator post 300 is installed in the ground to the level ofthe top edge 430 of reinforcement means 400 which forms an installationdepth indicator. As described previously, the presence of reinforcementmeans 400 facilitates the direct driving of post 300 into the ground 800either manually or by pneumatic means without the use of a pilot hole.

Referring now to FIG. 19, there is shown a number of different indicatorpost cross sections or extruded sectional profiles that are contemplatedto be within the scope of the present invention including, but notlimited to, the ribbed channel shaped type cross sections 510, 515 asexemplified by the first, second and third embodiments described herein,a substantially arcuate cross section 520 (where the radius of curvaturecan vary from 50 mm to 300 mm), an arcuate cross section incorporatingplanar edge portions 525, a ribbed arcuate cross section 530, agenerally planar cross section having a central broad rib andperpendicular edge portions 535 and a zigzag or concertina type crosssection 540. In those situations where a reinforcement member 400 may berequired it can be sized and shaped to substantially conform with thesectional profile of the indicator post.

It will be understood that the term “comprise” and any of itsderivatives (e.g. comprises, comprising) as used in this specificationis to be taken to be inclusive of features to which it refers, and isnot meant to exclude the presence of any additional features unlessotherwise stated or implied. The reference to any prior art in thisspecification is not, and should not be taken as, an acknowledgement ofany form of suggestion that such prior art forms part of the commongeneral knowledge.

Although illustrative embodiments of the present invention have beendescribed in the foregoing detailed description, it will be understoodthat the invention is not limited to the embodiment disclosed, but iscapable of numerous rearrangements, modifications and substitutionswithout departing from the scope of the invention as set forth anddefined by the following claims.

1. An indicator post comprising an elongate sheet of high strengthengineering polymer (HSEP) material, the elongate sheet beingresiliently bendable to enable the indicator post to revert uprightafter an impact.
 2. The indicator post of claim 1, wherein the HSEPmaterial is a UV stabilised extrudable polycarbonate.
 3. The indicatorpost of claim 1, wherein the UV stabilised extrudable polycarbonate isselected from any one of Makrolon 3101, Panlite polycarbonate, Novarexpolycarbonate, Carbine 8073 polycarbonate or any combination thereof. 4.The indicator post of claim 1, wherein the elongate sheet has asubstantially arcuate sectional profile.
 5. The indicator post of claim1, wherein the elongate sheet has a substantially channel shapedprofile.
 6. The indicator post of claim 1, wherein the width of theelongate sheet is approximately between 40 mm and 140 mm.
 7. Theindicator post of claim 1, wherein the thickness of the elongate sheetis approximately between 1 mm and 6 mm.
 8. The indicator post of claim1, further including ground engaging means to resist upward movement ofthe post after installation into the ground.
 9. The indicator post ofclaim 1, further comprising an installation depth indicator.
 10. Theindicator post of claim 1, further comprising a driveable base portionattached to the elongate sheet.
 11. The indicator post of claim 10,wherein the driveable base portion includes a star picket section. 12.The indicator post of claim 1, further comprising reinforcement means toreinforce a drivable portion of the elongate sheet.
 13. The indicatorpost of claim 12, wherein the reinforcement means substantially matchesthe shape of the drivable portion of the elongate sheet.
 14. Theindicator post of claim 12, wherein the reinforcement means comprises anelongate web portion attached to the elongate sheet.
 15. The indicatorpost of claim 14, wherein the elongate web portion includes a taperedend.
 16. The indicator post of claim 14, wherein the elongate sheet isformed of steel.
 17. The indicator post of claim 1, wherein theindicator post is a roadside post.
 18. A reinforcement means for anindicator post, the reinforcement means being attached to a driveableportion of the indicator post to reinforce the driveable portion fordriving into the ground.
 19. The reinforcement means of claim 18,wherein the reinforcement means substantially matches the shape of thedrivable portion of the indicator post.
 20. The reinforcement means ofclaim 18, wherein the reinforcement means comprises an elongate webportion.